Home construction recently has been in a conversion from the use of wooden frame construction to the use of metal frame construction. Wooden studs, particularly 2×4 and 2×6 studs have been replaced with metal studs. When performing home construction numerous holes or openings are required to be machined into the wall studs to permit the wiring, plumbing and other utility services to be placed behind walls and below floors of home construction.
Referring now to FIG. 1, a prior art spade drill 1 is shown for use in preparing hole 2 in a stud, for example a 2×4 wooden stud 3. The drill bit 1 includes a pilot 4 which extends from cutting face 5 of the drill bit 1. The pilot 4 contacts the stud 3 and provides a pilot or guide until the cutting face 5 contacts the stud 3 and serves to remove material from the stud 3 to provide opening 2.
Referring now to FIG. 1A, a 2×4 wooden stud 3 is shown in cross section. The 2×4 stud 3 has cross sectional dimensions of about 1½ inches by 3½ inches.
For metal studs, a hole saw 6 is typically used for preparing openings 7 in the metal studs 8. As shown in FIG. 2, the hole saw 6 includes a pilot 9 as well as a peripheral circular cutting surface 10. The pilot 9 first contacts the metal stud 8. After the pilot 9 has engaged the stud 8, the peripheral circular cutting surface 10 of the hole saw 6 creates a cylindrical opening in the metal stud 8 whereby a plug (not shown) is created from material of the metal stud 8. The plug is then removed from the hole saw 6.
Referring now to FIG. 2A, a metal construction wall stud 8 is shown in cross section. The metal stud 8 has cross sectional shape that is generally U-shaped with opposed lips 12 extending inwardly for the end of the U-shape. The metal stud 8 is typically made of 20 gauge mild steel and has a thickness TS of about 0.0359 inches.
The prior art hole saw 6 for use in preparing holes in metal stud 8 as shown in FIG. 2A is a relatively expensive tool. Further, the use of construction crews to build homes having either a combination of metal and wooden studs or having the frame crew of the construction company preparing both wooden framed homes and metal framed homes requires the framers to have drill bits for wood and separate drill bits for metal studs.
There is a need for a less expensive drill bit for use in preparing openings in metal wall studs.